Engine starter



June 3, 1941. Y SE'KELLA 2,244,265

ENGINE STARTER Filed Jan. 15, 1935 I N VENT OR.

BY 4mm @ekea AW -3:556.

Patented June 3, 1941 UNITED "res v ATENT Q FFIC-E ENGINE STARTER Application January 15, 1938, Serial No. 1'35,'198

6 Claims.

The present invention relates to engine starters and more particularly to an elastic yielding driving connection between a starting motor and the member of an engine to be started.

It is an object of the present invention to provide a novel engine starter gearing including a yielding coupling of simple construction capable of transmitting high torque without slippage or failure.

It is another object to provide such a device which is elastically compressible for the purpose of facilitating the meshing action of the gearing.

Further objects and advantages will be apparent "from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation partly in section of a preferred embodiment of the invention;

Fig. 2 is a section taken substantially on the line 2-2 of Fig. l; and

Fig. 3 is a detail in perspective of the various parts of the novel yielding connection, shown in disassembled relation.

In Fig. 1 of the drawing, there is indicated by numeral I a power shaft which may be the extended armature shaft of a starting motor, not shown. A sleeve 2 shown in detail in Fig. 3 is mounted on the power shaft l and anchored thereto by suitable means such as a pin 3 extending radially through a driving head 4 formed on the end of the sleeve 2, and through the power shaft I.

A screw shaft 5 also illustrated in detail in Fig. 3 is slidably mounted on the sleeve 2, being retained thereon by a stop nut E threaded on the end of the sleeve, and having a driven head I of non-circular contour adjacent the driving head 4 of the sleeve.

A pinion 8 is rotatably and siidably mounted on the shaft I for movement into and out of engagement with a member such as a flywheel gear 9 of the engine to be started. Means for actuating the pinion from the screw shaft 5 is provided comprising a barrel member ll anchored as indicated at 12 to the pinion and having a nut 13 non-rotatably connected thereto as indicated at l4 and arranged to engage the threads 15 of the screw shaft. The nut i3 is normally positioned on a smooth portion lb of the screw shaft by virtue of an anti-drift spring ll, but is urged into initial engagement with the screw threads by a reentry spring l8, and traverses the threads into engagement with the stop nut 6 when the screw shaft is rotated from the power shaft 1, whereby the pinion 8 is moved into engagement with the engine gear 9.

According to the present invention, a resilient yielding driving connection is provided between the sleeve 2 and the screw shaft 5. As here shown, this connection comprises a barrel member 19' non-rotatably mounted on the driving head 4 of sleeve 2 as by means of the double-D opening 2| in the barrel engaging the similar conformation of the driving head 4. The barrel i9 is retained on the driving head by suitable means such as a spring ring 22 seated in a groove 23 in the driving head and is preferably arranged to slightly overlap the ends of pin 3 and thus serve as a retaining means for said pin.

The periphery of the barrel i9 is provided with inturned vanes or flanges 24, and a sleeve 25 of elastically compressible material such as rubher or the like is mounted in the barrel and provided with peripheral longitudinal channels 28 formed to receive the vanes '24 so as to constrain the sleeve to rotate with the barrel [9.

The interior of the sleeve 25 is formed with a non-circular contour as indicated at 21 conforming to the exterior of the driven head 1 of the screw shaft 5, and slidably and non-rotatably receiving said driven head. Sliding movement of the driven head within the sleeve is limited bysuitable means such as a thrust ring 28 slidably mounted on the driven head 1 engaging the outer end of the sleeve 25 and seated against shoulders 29 formed at the terminationsof the flattened surfaces 3] of the driven head 1.

In the operation of this drive. rotation of the power shaft! by energization of the starting motor is transmitted through the pin 3 to the sleeve 4 and from thence through the barrel 19 to the periphery of the elastic sleeve 25. Rotation of the sleeve 25 is transmitted elastically thereby to the driven head 1 of the screw shaft whereby rotation thereof is caused to translate the nut I3 to move the pinion 8 into mesh with the flywheel gear 9. The meshing movement of the pinion is limited by the stop nut 15, whereupon further rotation of the power shaft causes the screw shaft 5 to be threaded to the left in Fig. 1, compressing the sleeve 25-until sufficient torque is built up to cause rotation of the engine gear 9. The transmission of torque to the starting pinion 8 is thus cushioned and rendered elastic by the circumferential yielding action of the sleeve 25, permitting angular variations between the barrel l9 and driven head 1, and, further, by the compressive yielding of the sleeve 25 permitting relative rotation between the screw shaft 5 and nut I3 as a consequence of longitudinal movement of the screw shaft due to fluctuations of torque.

It will be noted that due to the engagement of the vanes 24 of the barrel IS in the channels 26 of sleeve 25, and due to the conformation of the interior of the sleeve 25 with the flattened surfaces 3| of the driven head 1, slippage of the coupling is prevented while a yielding driving connection of exceptional efficiency is obtained due to the combined yielding action of the sleeve in torsion and compression.

If the meshing movement of the pinion 8 should be interrupted by abutment of the ends of the pinion and flywheel gear teeth, the endwise compressibility of the sleeve 25 permits the screw shaft 5 to retreat from its normal position against the stop nut 6, thus providing a time interval for the building up of friction between the threads l5 of the screw shaft and the interior threads of the nut l3, whereby the pinion is indexed into proper meshing relation and is thereupon snapped into meshing engagement with the flywheel gear by the expansion of the sleeve 25.

Although but one form of the invention has been shown and described in detail, it will be understood that other forms are possible and that various changes may be made in the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an engine starter, a shaft, a pinion movable thereon into and out of engagement with a member of an engine to be started, and means for actuating the pinion from the shaft including a barrel member fixed to the shaft, an elastically deformable sleeve member in the barrel slidably but non-rotatably connected thereto, a driven shaft in the sleeve slidably but non-rotatably connected to the sleeve, and means including said elastic sleeve member for yieldingly resisting longitudinal movement of the driven shaft.

2. In an engine starter, a shaft, a pinion movable thereon into and out of engagement with a member of an engine to be started, and means for actuating the pinion from, the shaft including a barrel member fixed to the shaft, an elastically deformable coupling member slidably but nonrotatably mounted in the barrel and having an axial opening of non-circular cross section, a driven shaft having a contour conforming to said opening, slidably received therein, and means including said elastic sleeve member for yieldingly resisting longitudinal movement of the driven shaft.

3. In an engine starter, a shaft, a pinion movable thereon into and out of engagement with a member of an engine to be started, and means for actuating the pinion from the shaft including a barrel member fixed to the shaft having inwardly extending axial flanges on its inner periphery, a sleeve of resilient material in the barrel having axial grooves receiving the flanges, and an axial opening of non-circular cross section; a driven shaft slidably but non-rotatably mounted in the sleeve, and means including said elastic sleeve member for yieldingly resisting longitudinal movement of the driven shaft.

4. In an engine starter drive, a motor shaft, a pinion slidably mounted thereon, means for moving the pinion into and out of mesh with a gear of the engine to be started including a screw shaft slidably mounted on the motor shaft, means for actuating the screw shaft including a driving member-in the form of a cylinder constricted at one end and anchored to the motor shaft, and a resilient coupling member in the form of a sleeve splined in the interior of the driving member, said screw shaft being seated in the interior of the coupling member and connected to rotate therewith, and an abutment member on the screw shaft engaging the end of the coupling member to thereby oppose longitudinal movement of the screw shaft.

5. In an engine starter drive, a motor shaft, a pinion slidably mounted thereon, and means for moving the pinion into and out of mesh with a gear of the engine to be started including a screw shaft slidably mounted on the motor shaft, a nut threaded on the screw shaft, and a barrel member connecting the nut and pinion, means for actuating the screw shaft including a driving member and an elastically deformable coupling sleeve splined thereto and connected to rotate with the screw shaft, and means on the screw shaft cooperating with the coupling sleeve to yieldingly resist longitudinal movement of the screw shaft.

6. In an engine starter, concentric rotary driving and driven members, a rubber sleeve interposed therebetween having an exterior cylindrical surface splined to the outer of said concentric members, and an internal surface of non-circular cross section, the inner of said concentric members having an external surface conforming to and slidably fitting the interior surface of the rubber sleeve, said rubber sleeve forming the sole torque connection between the driving and driven members, and torque-responsive means operated by the driven member for axially compressing the rubber sleeve.

YOUSTON SEKELLA. 

